No, but it might ruin your knees...
Also, per a controversial post a few months ago, a cyclist from our club was killed about 6 months ago when her front tire blew out at the bottom of a very long mountain downhill. I have not heard what caused the blowout, but, from my own experience and being "raised in the sport" by former bicycle mechanics, it's very possible that the tires were inflated to their maximum (perhaps 140 psi), and, due to the constant braking of mountain roads, perhaps caused the rims to overheat and caused the fatal blowout, so, being underinflated can be dangerous, but, like car tires, being over-inflated is just as bad.
Best to get a gage or have a tire pump with one, and keep about 80-85% of the maximum rated pressure in the tires at all times - that will allow for a good ride but keep the tires within safe limits.
Glades2
Last edited by Glades2; 05-04-09 at 01:24 PM.